Tyres for 18x8.5

[coyote]

Really? Why is 235 illegal?

No idea, but for a 05 GT lib that came with 215/45/17 it's illegal to go to 235/40/18?

In Qld you can only increase diameter by 15mm, which would be a fail on that score.

So maybe it's the diameter, rather than the width? In that case, better off staying with 17s.

[BJ]

I see, it must be because of the 17" rims. It is illegal to increase the overall diameter by too much, although I'm not sure how much, because of the effect on the speedo I think.
The diameter of 215/45/17 is 625mm.
The diameter of 235/40/18 is 645mm.
The diameter of 215/45/18 is 651mm.
Don't quote me, but I think this means you can't use them if the car had 17" wheels to start with, but if it's a spec B with 18" wheels it should be okay.

[jslayz]

just try some 245/35/18 or 255/35/18
They will be legal as OD is within guidelines

[jakey]

I've been reading about 'tyre stretching' would I be able to put my current tyres on my 17's 215/45Z/R17 onto 18x8's ?

Or should I just buy new tyres the tightarse within me is kicking in

[Doyab]

You can stretch with to a certain degree but not diameter

[jakey]

http://www.jaxquickfit.com.au/tyres/tip ... res-wheels

Plus Sizing your tyres, basically means installing tyres on to your vehicle that have a larger wheel diameter than the standard tyre fitment, while retaining the overall rolling radius the same, which is achieved by reducing the tyre profile.

?

[jslayz]

they mean you buy new tyres & rims to do it.

[jakey]

Ahhhh righto, there goes that great idea I had to save money